i965: Fix BRW_BATCH_STRUCT to specify RENDER_RING, not UNKNOWN_RING.
i965: Fix BRW_BATCH_STRUCT to specify RENDER_RING, not UNKNOWN_RING.

I missed this in the boolean -> enum conversion.  C cheerfully casts
false -> 0 -> UNKNOWN_RING.  On Gen4-5, this causes the render ring
prelude hook to get called in the middle of the batch, which is crazy.

BRW_BATCH_STRUCT is not used on Gen6+.

Fixes regressions since 395a32717df494353703f3581edcd3ba380f16d6
("i965: Introduce an UNKNOWN_RING state.").

Fixes "fips -v glxgears" on Ironlake.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Eric Anholt <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@anholt.net>

bkaradzic/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,mapbox/glsl-optimizer,benaadams/glsl-optimizer,tokyovigilante/glsl-optimizer,djreep81/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,wolf96/glsl-optimizer,jbarczak/glsl-optimizer,benaadams/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,metora/MesaGLSLCompiler,jbarczak/glsl-optimizer,bkaradzic/glsl-optimizer,dellis1972/glsl-optimizer,benaadams/glsl-optimizer,benaadams/glsl-optimizer,benaadams/glsl-optimizer,bkaradzic/glsl-optimizer,metora/MesaGLSLCompiler,mapbox/glsl-optimizer,dellis1972/glsl-optimizer,zz85/glsl-optimizer,mapbox/glsl-optimizer,mcanthony/glsl-optimizer,zeux/glsl-optimizer,dellis1972/glsl-optimizer,zeux/glsl-optimizer,jbarczak/glsl-optimizer,zeux/glsl-optimizer,zeux/glsl-optimizer,dellis1972/glsl-optimizer,metora/MesaGLSLCompiler,djreep81/glsl-optimizer,zz85/glsl-optimizer,jbarczak/glsl-optimizer,wolf96/glsl-optimizer,wolf96/glsl-optimizer,djreep81/glsl-optimizer,djreep81/glsl-optimizer,mcanthony/glsl-optimizer,mapbox/glsl-optimizer,mcanthony/glsl-optimizer,wolf96/glsl-optimizer,tokyovigilante/glsl-optimizer,benaadams/glsl-optimizer,zz85/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,mapbox/glsl-optimizer,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,zeux/glsl-optimizer,mcanthony/glsl-optimizer,dellis1972/glsl-optimizer,djreep81/glsl-optimizer,bkaradzic/glsl-optimizer